Author Topic: Howdy all! K75 owner from SF,CA  (Read 2873 times)

Offline nordaxe

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Howdy all! K75 owner from SF,CA
« on: June 16, 2024, 08:54:38 PM »
Hi!

Very excited to actually have an account here finally!

I have been a 1988 K75C owner for going on 6 years now and it's been the only real bike I have done all the work on myself, well with the help of you guys.

I can't express how helpful and informative this site has been on my journey. I am finally at this cross road where I need to ask some questions and hopefully the pros and super nice people I have seen on here can help.

Very glad to be here and once again, thanks!
  • Streets of San Francisco
  • 1988 K75C

Offline Chaos

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Re: Howdy all! K75 owner from SF,CA. Newbie but lurking for years!
« Reply #1 on: June 16, 2024, 09:10:52 PM »
welcome, but just signing up probably isn't all that much to get excited about.  What kind of problems you having?
  • sw ohio
1987 K75S    VIN 0231
Original owner, Original litter
200,000 miles (plus or minus) and 5 paint jobs
sold 6/23
2023 Ural 2WD sidecar (BMW's bastard step child)

Offline nordaxe

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Re: Howdy all! K75 owner from SF,CA. Newbie but lurking for years!
« Reply #2 on: June 16, 2024, 09:19:47 PM »
welcome, but just signing up probably isn't all that much to get excited about.  What kind of problems you having?

Thanks, excited to be able to post, just been blowing that off.

Bike was due for a tune up and knew it. Then it wasn't able to idle, almost sounded like a messed up plug or worse, plus oil light came on which really freaked me out and knew there was oil.

Did an oil change ( + trans and final drive ), fresh plugs ( boneyard kit ).

Now, when I turn the key, nada.... and the clock dies too. Did notice a fuse was blown, "sonder ausstattung" 3rd from bottom. But kinda new that wasn't it.

Spent past 3 days short searching, checking everything, whole harness, you name it can't figure it out.

  • Streets of San Francisco
  • 1988 K75C

Offline Laitch

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Re: Howdy all! K75 owner from SF,CA. Newbie but lurking for years!
« Reply #3 on: June 17, 2024, 08:00:23 AM »
Test the battery in two ways—the resting voltage and the voltage under load. Let us know the result.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline nordaxe

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  • Posts: 4
Re: Howdy all! K75 owner from SF,CA
« Reply #4 on: June 30, 2024, 06:50:03 PM »
Hi,

The battery has been fully tendered with a 12.7V reading from my meter and bought a topdiag tool as well... when I turn the key I pretty much get the same reading. Not sure if there is any better way to do load testing.

The bike was able to start with almost zero issue before. I usually let the starter relay getting stuck to let me know the battery is going.

The only changes have been since it last run was maintenance. Replaced the plugs and changed the oil ( main, trans and final drive ) and now it's more dead that its ever been.

At one point after jiggling the ignition switch, I did see the lights come on, hit the starter and then that's when I think I heard the auxillary fuse blow ( 3rd from the bottom )... not sure, but it didn't trigger the starter. That's why I tried to clean the ignition switch, which involved drilling out the little painted over screw since it was so old and stripped the minute I attempted to use a small screwdriver. I cleaned it thouroughly... but honestly, not sure how to test that thing. I did replace the fuse.

Been trying to test grounding all around where I can, pulled the tank off, checked the central grounding area.

The wiring diagrams in both manuals I have are pretty daunting when you really have no idea where to start and the clock dying when I turn the ignition felt like an easy ground thing.

Last time I had issues with the starter relay, I replaced the whole wiring harness since it literally melted a ton of wires, bought 3 different starter relays to find out my battery was bad...

Not sure if that is where I should start again, but I am pretty bummed at this point and don't want to give up...
  • Streets of San Francisco
  • 1988 K75C

Offline Past-my-Prime

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Re: Howdy all! K75 owner from SF,CA
« Reply #5 on: June 30, 2024, 08:54:18 PM »
I’ve found that a battery can provide lots of volts when you check with a meter but will drop to 10 or lower when it’s trying to turn the starter. That’s when I know it’s time to buy a new battery. Varies but usually every few years. Except I’ve now had a lithium for quite a while and it’s been fine.
  • North Shore of Lake Superior (in my garage)
  • BRICK: 1989 K75 RT - Rocinante; NON-BRICK: 2007 F650 GS Dakar - Betty Blue

Offline nordaxe

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Re: Howdy all! K75 owner from SF,CA
« Reply #6 on: July 06, 2024, 09:35:22 PM »
Thanks for the responses and yes it came down to just buying a new battery ( fresh YT19BL-BS) ....

Amazing, last time I was in this spot ( dead in the water for a couple weeks, it was the battery as well ). I bought a load tester, but both my old batteries are coming up fine on this thing. Will have to come up with a better test. My poor ignition switch got nearly destroyed by overthinking this, at least it's clean :)

Will look into a lithium battery for sure
  • Streets of San Francisco
  • 1988 K75C

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